These changes would also increase consumer protections for those who are unable to fly due to pandemic-related reasons, even if they had nonrefundable tickets.
Passengers would be entitled to travel credits or vouchers that do not expire or, if the airline received significant government financial assistance, a full refund.
New rules proposed to fix lagging airline disruption
Previously, airlines only had to refund passengers if they "significantly change" a flight.
However, the world of air travel has changed a lot in the last three years and flight schedules are increasingly prone to change or cancellation.
Since the start of the pandemic, the department said they had received a "flood" of complaints from passengers whose flights were delayed, cancelled or affected by Covid-19.
In June and July alone, around 40,000 flights were cancelled according to data from FlightAware.
In June, Transportation Secretary Pete Buttigieg told airline CEOs to fix the summer flight schedules but told CNN the proposed changes had "been in the works for some time".
The department itself has received pressure to crack down on airlines and protect consumers.
In late July Democratic Senator Elizabeth Warren of Massachusetts and Alex Padilla of California demanded the department use their authority more "aggressively".
A group of lawmakers also wrote a letter asking them to force airlines to pay fines and compensate passengers when flights were overbooked.
On Wednesday, New York Attorney General Letitia James said the department needed to "increase its oversight and regulation of airlines that are skirting the rules and causing disruptions for travellers."
According to James, this should involve requiring airlines to provide full or partial refunds for cancelled and rescheduled flights.
They should also be limited to only selling flights they have enough staffing for, said James.